Modeling of self-heating in GaAs/AlGaAs HBTs for accurate circuit and device analysis

An improved HBT (heterojunction bipolar transistor) large signal model has been developed which allows calculation of intrinsic device temperature as a function of the dissipated power. The time dependence of this power effect is evaluated using pulsed on-wafer measurements. The calculated temperatures are proved to be correct by diode drop measurements with a pair of standard transistors. Simplified numerical simulations of the three-dimensional heat equations give similar results. An additional test structure-a broadband amplifier with a Darlington connected pair of transistors-is simulated to predict the intrinsic device temperatures and show reliability under normal operating conditions. Their thermal behaviors are confirmed with liquid crystal measurement techniques.<<ETX>>

[1]  R. D. Lindsted,et al.  Steady-state junction temperatures of semiconductor chips , 1972 .

[2]  David J. Allstot,et al.  Modeling of frequency and temperature effects in GaAs MESFETs , 1990 .

[3]  M. E. Hafizi,et al.  Reliability analysis of GaAs/AlGaAs HBTs under forward current/temperature stress , 1990, 12th Annual Symposium on Gallium Arsenide Integrated Circuit (GaAs IC).

[4]  P. Baureis,et al.  A new large signal model for heterojunction bipolar transistors including temperature effects , 1991, Proceedings of the IEEE 1991 Custom Integrated Circuits Conference.